Cleaning Or Replacing The Npd Collecting Electrode - Thermo Scientific TRACE 1600 Hardware Manual

Cleaning or Replacing the NPD Collecting Electrode

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22. Increase the temperature to the operating value: 300 to 320 °C is recommended. Allow
15 minutes for equilibration.
23. Check the NPD leakage current. If > 2.0 pA, verify the installation.
Note Some of the cleaning procedures in this section require the use of methanol.
If methanol is unavailable or prohibited, substitute LCMS-grade or GC-grade ethanol
or isopropyl alcohol. Do not use denatured ethanol as it may contain impurities that
contaminate the GC-MS system.
 To clean or replace the NPD collecting electrode
1. Put the GC in standby condition.
2. Switch off the thermionic source. Hydrogen and air are automatically closed.
3. Cool the detector to room temperature.
4. Set the make-up gas off.
Note By pressing the Maintenance button, the GC cool down is automatically
carried out.
5. Power off the GC.
a. Push down the power switch (breaker), located at the back of the instrument, to the
position O.
b. Unplug the power cable from the AC Input connector into the back of the GC and
from the wall outlet.
6. Unplug the power cable from the AC input connector of the NPD Thermionic Source
Power Module and from the wall outlet.
If other external modules are present, unplug the power cable from the AC Input
connector of each module, and from the wall outlet.
7. Unplug the signal cable from the detector module. See
4
Performing Detectors Routine Maintenance
Maintaining a Nitrogen Phosphorous Detector (NPD)
Figure 137.
TRACE 1600/1610 Hardware Manual 169